Former chess champion Bobby Fischer announced plans Monday to marry a leading Japanese chess official and appealed to Secretary of State Colin L. Powell to help him renounce his U.S. citizenship, the latest in a series of moves to block attempts to deport him to the United States.

Fischer, 61, wanted in the United States for violating international sanctions by playing a match in Yugoslavia in 1992, was detained in Japan last month while trying to travel on a revoked U.S. passport.

Fischer's lawyer, Masako Suzuki, said the former world champion and the president of the Japan Chess Association, Miyoko Watai, had signed marriage papers that would be submitted later Monday.

The two had been living together since 2000 and decided to legally formalize their relationship, Suzuki said in a statement. She did not explain what prompted the couple to do so now and it was not immediately clear how marriage to a Japanese citizen would affect the efforts to extradite Fischer. Calls to Watai's office were not returned Monday.

Fischer, meanwhile, was pursuing an effort to forsake his U.S. citizenship, although that could leave him stateless, Suzuki said.

The lawyer faxed a letter to Powell and the U.S. Embassy in Japan on Monday demanding that an American consular officer be sent to see Fischer in detention to accept his renunciation of U.S. citizenship.

In the letter, Suzuki accused the embassy of insisting that Fischer appear there in person even though Japanese officials will not allow him to make the trip.

Fischer already has applied for asylum in Japan, claiming he was being "persecuted" by the United States. He also had plans to apply for refugee status with the U.N. High Commissioner for Refugees and was looking for other countries that might accept him as a refugee, Suzuki has said.

Fischer's animosity toward the United States is well-known. He once praised the Sept. 11, 2001, terrorist attacks, saying in a radio interview that the United States should be "wiped out." Over the years, Fischer has given occasional interviews, often digressing into anti-Semitic rants and accusing American officials of hounding him.

Former chess champion Bobby Fischer plans to marry a Japanese chess official.